[ODE] ODE slow on itanium?

[Francois Beaune]

one thing to keep in mind is that itanium needs heavy
assistance from the compiler. i don't know how good
is gcc for itanium, but i suspect it is largely inferior to
a native compiler for that processor.

do you have access to the intel compiler for itanium?

francois

----- Original Message ----- 
From: "Andreas Fredriksson" <deplinenoise at gmail.com>
To: "Bill Sellers" <wis at mac.com>
Cc: "ode-list list" <ode at q12.org>
Sent: Monday, December 04, 2006 20:38
Subject: Re: [ODE] ODE slow on itanium?


> On 12/3/06, Bill Sellers <wis at mac.com> wrote:
>> Hi All,
>>
>> I've just been doing some benchmarking of my simulation on various
>> processors and they all behave about as I expect except for a truly
>> dreadful showing on a recent 1.6GHz Itanium system. It's over 3 times
>> slower than an Opteron 252 which is hardly cutting edge anymore, and
>> over twice as slow as the Xeon 5160 in my MacPro. They are all
>> compiled with gcc using the standard "-O3 -ffastmath" options. Anyone
>> got any idea what's wrong since I don't think the Itanium should be
>> this slow...
> 
> Make sure you're not gettig denormals propagating through your
> simulation; from what I've heard they're very slow on Itanium. They're
> also very slow on AMD and Intel hardware, unless by chance the
> precision of the simulation is different enough that you're only
> seeing the problem on the Itanium box.
> 
> Good luck,
> Andreas
> 
> -- 
> My other car is a cons.
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